Subsidizing Technological Innovations in the Presence of R&D Spillovers

We analyze a situation where a principal wants to induce firms to produce an output, e.g. electricity from renewable energy sources. Firms can undertake non-contractible investments to reduce production costs of the output. Parts of these investments spills over and also reduce production costs of the other firm. Comparing the general price subsidy and an innovation tournament, we find that the principal's expected cost of implementing a given expected output are always higher under the tournament, even though this scheme may lead to more innovation.